This may be one Mika match that I think Mika wins. Yeah it sucks when he knocks you down. It sucks when you knock him down too.
Throw s. lp out liberally. Just do it. Don’t jam on it but maneuver around and stick it out there. Gief really hates Mika’s jab, he’s slow moving, slow poking, it beats EVERYTHING he does. He has no answer to it. It’s a 3 frame jab with a lot of reach.
After you touch him with it like 15 times, start walking forward. He can’t flex it, that’s silly. Just do s. lp, s. lp. Link timing. Is he going to flex both? Yeah he can, is he going to keep doing that? Going to be risky to do that eh?
Gief should have NO offense. Don’t let him do a damn thing. This is Mika’s fight! Enjoy it. For gods sake do not do charged rh because that’s extremely easy to v skill and spd or something. Leave that move alone. Feel free to jab him more and more and build meter, then use Mika’s best tool against Gief:
Mika’s best tool vs Gief: s. mp linked qcf+pp. Easy stuff and gief eats it all day every day. Not mp xx qcf+pp. mp LINKED qcf+pp. Gief gets destroyed by this. It’s a pretty easy hit confirm and s. mp at MAX RANGE still links into this and gief really can’t do anything about it.
Also when you see him trying to be clever and use his fp toys you can just backdash, dash forward, and punish him. Once you start looking for it it’s pretty easy to do. At many ranges you can backdash, clip him with s. mp on his whiff and combo your qcf+pp.
If gief starts jumping, Mika can actually anti air him with her wingless airplane. You don’t need to be fast and use ex qcf+kk (3 frames). qcf+mk (5 frames, I believe?) is almost always sufficient. Obviously if he jumps right on your head poorly then d+mp is fine but if he jumps over your for a crossup you can do d+fp to escape in most cases.
I hope that helps. Yeah you can’t get knocked down by him or you’re in a 50/50. So…put him in more 50/50s, he has the same problems against you. Really nothing else to it. This is better for Mika though, she beats him in neutral. 4.5/5.5 Mika wins.